swift - UILocalNotification 的 userInfo 对象的符合性要求

Question

使用 Swift-2.2，

我想将“结构”或“类对象”传递给 UILocalNotification 的 userInfo。 (参见下面的代码说明)。

你能告诉我这个结构需要如何更改才能符合 UserInfo 的要求吗？

我读到了一些内容

a) UserInfo 不能是一个结构(但我也尝试过使用一个类 - 它也不起作用)

b)“plist 类型”一致性 --> 但我该怎么做？

c) “NSCoder”和“NSObject”一致性 --> 但我该怎么做？

我运行下面的代码时收到的错误消息是:

“无法序列化用户信息”

感谢您对此提供的任何帮助。

struct MeetingData {
    let title: String
    let uuid: String
    let startDate: NSDate
    let endDate: NSDate
}

let notification = UILocalNotification()
notification.category = "some_category"
notification.alertLaunchImage = "Logo"
notification.fireDate = NSDate(timeIntervalSinceNow: 10)
notification.alertBody = "Data-Collection Request!"
//        notification.alertAction = "I want to participate"
notification.soundName = UILocalNotificationDefaultSoundName

let myData = MeetingData(title: "myTitle",
                          uuid: "myUUID",
                     startDate: NSDate(),
                       endDate: NSDate(timeIntervalSinceNow: 10))

// that's where everything crashes !!!!!!!!!!!!!!
notification.userInfo = ["myKey": myData] as [String: AnyObject]

Answer 1

正如 UILocalNotification.userInfo 的文档所述:

You may add arbitrary key-value pairs to this dictionary. However, the keys and values must be valid property-list types; if any are not, an exception is raised.

您需要自己将数据转换为这种类型。您可能想做这样的事情:

enum Keys {
    static let title = "title"
    static let uuid = "uuid"
    static let startDate = "startDate"
    static let endDate = "endDate"
}
extension MeetingData {
    func dictionaryRepresentation() -> NSDictionary {
        return [Keys.title: title,
                Keys.uuid: uuid,
                Keys.startDate: startDate,
                Keys.endDate: endDate]
    }
    init?(dictionaryRepresentation dict: NSDictionary) {
        if let title = dict[Keys.title] as? String,
            let uuid = dict[Keys.uuid] as? String,
            let startDate = dict[Keys.startDate] as? NSDate,
            let endDate = dict[Keys.endDate] as? NSDate
        {
            self.init(title: title, uuid: uuid, startDate: startDate, endDate: endDate)
        } else {
            return nil
        }
    }
}

然后您可以使用 myData.dictionaryRepresentation() 转换为字典，并使用 MeetingData(dictionaryRepresentation: ...) 从字典转换。